WALSH DESCRIPTIONS OF N. AM. HYMENOPTERA. 99 



black, h as long as the body, the ist joint of the ilagellum twice as long 

 as wide, the 2d joint J longer than wide, the following ones square. Thorax 

 polished, with fine, rather close-set, shallow punctures; parapsidal grooves 

 subobsolete. Scutel flat, elongate semi-oval, with a very distinct lateral 

 and terminal carina, and a transverse, deeply impressed stria at its base. 

 Metathorax with 4 longitudinal carinae, and a posterior lunate area, but 

 no cross-carinse. Tegulse whitish. Abdomen subopaque, with close-set, 

 fine punctures. Joint i longer by \ than wide, i wider behind than be- 

 fore, with five longitudinal, acute, lofty carin<e distinctly visible from 

 above, viz. : the 2 usual dorsal ones and a third in the terminal | of the 

 space enclosed between them, and the 2 usual lateral ones which are here 

 elevated on the dorsum so as to appear detached from the lateral edge of 

 the joint whert viewed from above. Joint 2 with 3 such carinae, the 2 outer 

 ones a continuation of the lateral carinae of joint i and the middle one a 

 continuation of its middle carina. Joint 3 with i carina only, a continua- 

 tion of the middle one ; and joint 4 with the same but only prolonged half 

 way to its tip. Ovipositor exserted and as well as its sheaths blackish. 

 Venter whitish. Z,e^5 rufous immaculate. W^««^5 subhyaline, veins and 

 stigma black. Length $ .27 inch. Front wing $ .17 inch. 



The (^differs from the $ only as follows : i. The entire face and a short 

 orbit extending just beyond the antennae, the cheeks, clypeus, and mandi- 

 bles except their teeth, are all pale yellow immaculate ; and the tubercle 

 on the face is obsolete. 2. The antennae are § as long as the body, the ist 

 joint of the flagellum twice as long as wide, the 2d i longer than wide, 

 and the following ones \ longer than wide; and the ist joint of the scape 

 is yellow beneath. 3d. The 4 anterior coxae are whitish at tip. Length 

 ^ .30 inch. Front wing d* .20 inch. 



Two rT, one ?. Differs from Tryphon carinatus^ Cress., by 

 the 2d abdominal joint having 3 (not i) carinae, by the 3d and 4th 

 being unicarinate (not simple), and by the protuberant face. Very 

 distinct from all other allied N. A. species by the short wings and 

 the remarkable carinae of the abdomen. One f^ was bred from a 

 small Lepidopterous pupa. 



[Genus ORTHOCENTRUS, Grav.] 



Face and cheeks as prominent as in Exochus. Antennae mo- 

 derate, joints not unusually short, the ist joint of the scapus trun- 

 cate rather obliquely from above downwards, the 2d joint large, 

 Scutel hunched, its sides declivous. Abdomen sessile, elongate- 

 oval, almost elongate-oblong in c?, the 2d joint in c? rather longer 

 than wide. Ovipositor very short. Legs somewhat short and 

 robust, the hind coxae and femora much incrassated ; tarsal claws, 

 especially those of the hind legs, nearly as long as the last tarsal 

 joint, and suddenly dilated on their basal \ into a large tooth, the 

 2 teeth together simulating a 6th tarsal joint ; pulvillus very nar- 



